A British soldier was killed by a burst of machine gun fire while on sentry duty at his regiment's base in central Basra, the Ministry of Defence disclosed yesterday.

He was named last night as Kingsman Jamie Hancock, 19, from the 2nd Battalion Duke of Lancaster's Regiment. He was shot on Monday as he was manning a sangar - a sentry tower - at the Old State Building, one of the British bases in the southern Iraqi city. He was part of his battalion's advance party and had been in Iraq for two weeks.

The machine gun fire is believed to have come from a building opposite the sentry tower, defence officials said.

Kingsman Hancock lived near Wigan, Greater Manchester, with his brother, also a serving soldier. His company commander, Major Chris Job, said: "His enthusiasm was boundless and the fearless spirit with which he lived was amply demonstrated by his decision to volunteer for this Iraq tour. He was a magnet for his peers, who were drawn by his infectious sense of fun and all-embracing nature."

His family said they were "deeply shocked", adding in a statement: "We are and always will be very proud of him and all that he achieved." They asked for their privacy to be respected.

The defence secretary, Des Browne, said he was "deeply saddened" by the soldier's death. "Our brave forces are striving to build a better future for the people of Iraq and this is a stark reminder to us all of the dangers they face there," he said. Monday's attack was the third in which British soldiers have died in or just outside their base in little over a month. On October 1, Lance Corporal Dennis Brady, a Royal Army Medical Corps reservist, was killed by mortar fire at the Shaat al-Arab hotel base in Basra. On October 27, Lieutenant Tom Tanswell, of the Royal Artillery, was killed just outside the British base at Shaibah on the city outskirts.

Monday's death brings the total number of British troops killed in operations in Iraq to 121. The MoD attributes 91 of the deaths to hostile action. Most of the attacks, by gun or rocket fire or improvised roadside bombs, have been on British army patrols. Insurgents now appear to be taking the attack to British bases.

British commanders are engaged in Operation Sinbad, involving 3,000 British troops and Iraqi forces, in an attempt to rid Basra of serious criminals, corrupt officials and smugglers. They are facing an uphill struggle against insurgents who also consist of Shia militia with their supporters infiltrating the local police force.

Yet senior Iraqi security officials in Basra have complained that tougher action by British forces aggravates the problem. Four Iraqi police officers were recently arrested by British soldiers who found a bomb in their car. The Iraqis claimed they had discovered the bomb and were disposing of it. British troops subsequently released them.

The government was accused yesterday of giving a "temporising and woolly" response to an inquiry by an all-party committee of peers into the role of parliament over the deployment of British forces overseas.

Lord Holme, chairman of the Lords constitution committee, said the government's response to its report, Waging War: Parliament's Role and Responsibility, demonstrated "a complete failure on the part of the government to give any real consideration to our key recommendation - that the role of parliament in the deployment of forces outside the UK should be established in a new convention".

The government says in its response: "The ability of the executive to take decisions flexibly and quickly using prerogative powers remains an important cornerstone of our democracy". However, it adds: "Whilst the government could in theory deploy the armed forces overseas without the support of parliament, it would be almost impossible to identify a set of circumstances which would allow the government to act without parliamentary support."